Self-aligned InP DHBTs for 150 GHz digital and mixed signal circuits

A production oriented manufacturing process for Indium Phosphide double-heterojunction bipolar transistor (DHBT) devices that enables 150 GHz digital and mixed signal circuits is presented. These transistors have cut-off frequency (f) and maximum oscillation frequency (f/sub max/) both over 300 GHz and open-base breakdown voltage (BV/sub ceo/) over 4 V. Common Mode Logic (CML) ring oscillators have exhibited 1.95 ps gate delay and Emitter Coupled Logic (ECL) static frequency dividers that operate up to 152 GHz have been demonstrated to benchmark this InP process technology. A 4:1 multiplexer for 100 Gb/s circuits is discussed along with a Gilbert cell Variable Gain Amplifier with excess of 50 GHz bandwidth and record gain bandwidth product of 397 GHz.